android_jni: Support RGBA_F16 Bitmaps

libavif now supports conversion of RGBA pixels into F16 formats
for AVIF images with depths 10 and 12. Make use of that feature to
support RGBA_F16 bitmaps on the android JNI wrapper.

Note that apps can still pass an ARGB_8888 Bitmap for 10/12 bit
images and the wrapper will merely downscale them to 8 bits in that
case (existing behavior). Also as an added behavior, apps can now
pass RGBA_F16 bitmap for 8-bit images as well since libavif supports
converting 8-bit RGBA pixels to 16-bit half floats.

android_jni/avifandroidjni/src/main/java/org/aomedia/avif/android/AvifDecoder.java

diff --git a/android_jni/avifandroidjni/src/main/java/org/aomedia/avif/android/AvifDecoder.java b/android_jni/avifandroidjni/src/main/java/org/aomedia/avif/android/AvifDecoder.java
index bed181a..5baede3 100644
--- a/android_jni/avifandroidjni/src/main/java/org/aomedia/avif/android/AvifDecoder.java
+++ b/android_jni/avifandroidjni/src/main/java/org/aomedia/avif/android/AvifDecoder.java
@@ -20,10 +20,11 @@
   // This is a utility class and cannot be instantiated.
   private AvifDecoder() {}
 
-  /** Contains information about the AVIF Image dimensions. */
+  /** Contains information about the AVIF Image. */
   public static class Info {
     public int width;
     public int height;
+    public int depth;
   }
 
   /**

android_jni/avifandroidjni/src/main/jni/libavif_jni.cc

diff --git a/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc b/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc
index 24a5fc0..2ad5284 100644
--- a/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc
+++ b/android_jni/avifandroidjni/src/main/jni/libavif_jni.cc
@@ -23,6 +23,7 @@
 
 jfieldID global_info_width;
 jfieldID global_info_height;
+jfieldID global_info_depth;
 
 // RAII wrapper class that properly frees the decoder related objects on
 // destruction.
@@ -75,6 +76,7 @@
       env->FindClass("org/aomedia/avif/android/AvifDecoder$Info");
   global_info_width = env->GetFieldID(info_class, "width", "I");
   global_info_height = env->GetFieldID(info_class, "height", "I");
+  global_info_depth = env->GetFieldID(info_class, "depth", "I");
   return JNI_VERSION_1_6;
 }
 
@@ -94,6 +96,7 @@
   }
   env->SetIntField(info, global_info_width, decoder.decoder->image->width);
   env->SetIntField(info, global_info_height, decoder.decoder->image->height);
+  env->SetIntField(info, global_info_depth, decoder.decoder->image->depth);
   return true;
 }
 
@@ -124,8 +127,9 @@
         decoder.decoder->image->height);
     return false;
   }
-  // Ensure that the bitmap format is RGBA_8888. For now, we only support that.
-  if (bitmap_info.format != ANDROID_BITMAP_FORMAT_RGBA_8888) {
+  // Ensure that the bitmap format is either RGBA_8888 or RGBA_F16.
+  if (bitmap_info.format != ANDROID_BITMAP_FORMAT_RGBA_8888 &&
+      bitmap_info.format != ANDROID_BITMAP_FORMAT_RGBA_F16) {
     LOGE("Bitmap format (%d) is not supported.", bitmap_info.format);
     return false;
   }
@@ -137,8 +141,12 @@
   }
   avifRGBImage rgb_image;
   avifRGBImageSetDefaults(&rgb_image, decoder.decoder->image);
-  // For now, we only support 8 bit RGBA output.
-  rgb_image.depth = 8;
+  if (bitmap_info.format == ANDROID_BITMAP_FORMAT_RGBA_F16) {
+    rgb_image.depth = 16;
+    rgb_image.isFloat = AVIF_TRUE;
+  } else {
+    rgb_image.depth = 8;
+  }
   rgb_image.pixels = static_cast<uint8_t*>(bitmap_pixels);
   rgb_image.rowBytes = bitmap_info.stride;
   res = avifImageYUVToRGB(decoder.decoder->image, &rgb_image);